Cyclic nucleotide phosphodiesterases

Cyclic nucleotide second messengers (cAMP and cGMP) play a central role in signal transduction and regulation of physiologic responses. Their intracel lular levels are controlled by the complex superfamily of cyclic nucleotide phosphodiesterase (PDE) enzymes. Continuing advances in our understanding of the molecular pharmacology of these enzymes has led to the development o f selective inhibitors as therapeutic agents for disease states ranging fro m cancer and heart failure to depression and sexual dysfunction. Several PD E types have been identified as therapeutic targets for immune/inflammatory diseases. This article briefly reviews the available in vitro, preclinical , and clinical data supporting the potential for selective PDE inhibitors a s immunomodulatory agents.